1. Field of the Invention
The present invention relates to a method and apparatus for beheading and gutting fish such as Alaska pollacks, while they are kept straightforward, in a pretreating step which is to be carried out before they are processed into a material for ground fish meat.
2. Prior Art
In order to process fish such as Alaska pollacks into a material for ground fish meat, they are first beheaded and gutted and then supplied to a unit 12 for removing bones such as spinal bones (hereinafter referred simply as the deboner), as illustrated in FIG. 8 providing a schematic illustration of the deboner and FIGS. 9a, 9b and 9c being end views taken along the lines A--A, B--B and C--C of FIG. 8, respectively, where they are processed into a fish meat product ridded of main bones. Referring to the deboner 12, a beheaded and gutted fish is carried on a belt 12a, while its both sides are firmly held with its ventral side down, to a venter cutter 12b with which the ventral side is cut open (see FIG. 9a), then to first deboner rotary cutters 12c placed and driven on both sides of and below the belt 12a, with which the ribs are cut off (see FIG. 9b), and finally to second rotary deboner cutters 12d placed and driven on both side of and below the belt 12a, with which the spinal bone is cut off (see FIG. 9c). Thus, the fish has to be firmly held and delivered on the deboner 12 while the spinal bone is located in parallel with the delivery direction.
Heretofore, the removal of the guts from fish supplied to the deboner 12 has been manually carried out because, in the case of Alaska pollacks in particular, there is contained valuable "cod roes" adjacent to the guts. As disclosed in, for instance, Japanese Patent Publication No. 59-26257 entitled "Cod Roe Remover", however, there has recently been developed equipment in which the cod roe with the guts is squeezed out of the venter of a fish previously beheaded by mechanical means so as to cut down labor cost and reduce the processing time.
However, the following problem arises with such a cod roe remover. A fish is beheaded while firmly held and suspended at the rear region of the trunk and the tail region by a carrier unit comprising a carrier belt and a carrier chain, and the guts and cod roes are then squeezed out by applying pressure to the ventral region. Since this equipment is designed with a main view to obtaining cod roes rather than fish meat, some moment acts upon the firmly held region of the fish so that the fish yields, when the guts with cod roes are squeezed out of the fish by applying pressure to the ventral region. This means that when the fish yields in this manner, the fish may be unlikely to be firmly held on the above deboner 12 upon supplied thereto. Even though the fish is successfully held on the deboner, such inconvenience as the spinal bone left in fish meat is encountered, since the spinal bone is not in parallel with the delivery direction of the fish. Required to restore a yielding fish to the original state is labor or considerably sophisticated equipment. As a result, it has been impossible to feed fish directly to processing steps for obtaining fish meat in the form of a material for ground fish meat.
Additionally, this defect implies that the above deboner 12 cannot be mounted contiguous to such a cod roe remover and, hence, there is needed a room for correcting yielding fish in front of said deboner 12. However, grave difficulty is encountered in providing such room on a ship which is given only a relatively limited space for immediate treatments of catches of fish. This places some limitation upon throughputs, especially when fish is caught in big quantity.